A model of the magnetospheric electric convection field

Volland, H.

doi:10.1029/ja083ia06p02695

Cited by 197 publications

(104 citation statements)

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“…Using the Tsyganenko TS05 magnetic field model (Tsyganenko, 1995;Tsyganenko and Sitnov, 2005) and the VollandStern electric field model (Stern, 1975;Volland, 1978) to simulate the magnetosphere, a fairly realistic model can be created to trace the drift, bounce, and gyration of charged particles at varying energies, charges, pitch angles, and masses.…”

Section: Modeling Charged Particles In Magnetospherementioning

confidence: 99%

The Earth's magnetopause as a source and sink for equatorial nightside energetic charged particles

Klida

Fritz

2009

Ann. Geophys.

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Abstract. The Imaging Proton Spectrometer (IPS) and the Imaging Electron Spectrometer (IES) on the Polar satellite have measured temporary deviations in the isotropy of the pitch angle distributions (PADs) of charged particles in the inner magnetosphere. As Polar passes through the nightside equatorial region, the IPS and IES observe dropouts of charged particles with pitch angles near 90 • , known as butterfly distributions caused by the shadowing of the magnetopause. Additionally, Polar observes a lower energy (<60 keV) intensification of locally mirroring ions while simultaneously detecting butterfly PADs in both higher energy ions and electrons. While it is accepted that charged particles can be lost to the magnetopause due to shadowing effects, the modeling here can suggest that the magnetopause can also be a direct source for particles observed in magnetosphere, with a strong dependence upon both pitch angle and particle energy.

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Section: Modeling Charged Particles In Magnetospherementioning

confidence: 99%

The Earth's magnetopause as a source and sink for equatorial nightside energetic charged particles

Klida

Fritz

2009

Ann. Geophys.

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“…INTRODUCTION Recently, we combined a plasma convection model and an ionospheric-atmospheric composition model in order to study the dynamics of the high-latitude F region. The plasma convection model, which is based on the work of Volland [1978], includes the offset between the geographic and geomagnetic poles, the tendency of plasma to corotate about the geographic pole, and a dawn/dusk magnetospheric electric field mapped to a circular region in the ionosphere about a center offset by 5° in the antisunward direction from the magnetic pole [Meng et al, 1977]. Equatorward of the circle the potential diminishes radially and varies inversely as the fourth power of sine magnetic co-latitude.…”

mentioning

confidence: 99%

Plasma density features associated with strong convection in the winter high‐latitude F region

Sojka¹,

Raitt²,

Schunk³

1981

J. Geophys. Res.

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We combined a simple plasma convection model with an ionospheric-atmospheric composition model in order to study the plasma density features associated with strong convection in the winter high-latitude F region. Our numerical study produced time-dependent, three-dimensional, ion density distributions for the ions NO +, O 2 +, N2 + , 0 + , N +, and He +. We covered the highlatitude ionosphere above 42° N magnetic latitude and at altitudes between 160 and 800 km for a time period of one complete day. From our study, we found the following: (1) For strong convection, the electron density exhibits a significant variation with altitude, latitude, longitude, and universal time. A similar result was obtained in our previous study dealing with a weak convection model. (2) For strong convection, ionospheric features, such as the main trough, the aurorally produced ionization peaks, the polar hole, and the tongue of ionization, are evident but they are modified in comparison with those found for slow convection. (3) For strong convection, the tongue of ionization is much more pronounced than for weak convection. (4) The polar hole that is associated with quiet geomagnetic activity conditions does not form when the plasma convection is strong. (5) For strong convection, a new polar hole appears in the polar cap at certain universal times. This new polar hole is associated with large downward, electrodynamic plasma drifts. (6) For strong convection, the main or mid-latitude electron density trough is not as deep as that found for a weak convection model. However, it is still strongly UT dependent. (7) The ionospheric parameters N mF2' hmFt, and the topside plasma density scale height exhibit an appreciable variation over the polar region at a given UT.

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“…As revealed by MES-SENGER , a 484 km northward offset of the planetary magnetic field was also accounted for in this model. As for the large-scale convection electric field, a twocell Volland-Stern pattern (e.g., Volland, 1978) was considered in first approximation. Also, the full equation of motion was used to compute the ion trajectories in order to account for possible nonadiabatic transport features.…”

Section: Parallel Energization Of Heavy Planetary Materialsmentioning

confidence: 99%

On the supply of heavy planetary material to the magnetotail of Mercury

Delcourt

2013

Ann. Geophys.

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Abstract.We examine the transport of low-energy heavy ions of planetary origin (O + , Na + , Ca + ) in the magnetosphere of Mercury. We show that, in contrast to Earth, these ions are abruptly energized after ejection into the magnetosphere due to enhanced curvature-related parallel acceleration. Regardless of their mass-to-charge ratio, the parallel speed of these ions is rapidly raised up to ∼ 2 V E×B (denoting by V E×B the magnitude of the local E × B drift speed), in a like manner to Fermi-type acceleration by a moving magnetic mirror. This parallel energization is such that ions with very low initial energies (a few tenths of eVs) can overcome gravity and, regardless of species or convection rate, are transported over comparable distances into the nightside magnetosphere. The region of space where these ions reach the magnetotail is found to extend over altitudes similar to those where enhanced densities are noticeable in the MESSENGER data, viz., from ∼ 1000 km up to ∼ 6000 km in the pre-midnight sector. The observed density enhancements may thus follow from E × B related focusing of planetary material of dayside origin into the magnetotail. Due to the planetary magnetic field offset, an asymmetry is found between drift paths anchored in the Northern and Southern hemispheres, which puts forward a predominant role of heavy material originating in the Northern Hemisphere in populating the innermost region of Mercury's magnetotail.

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A model of the magnetospheric electric convection field

Cited by 197 publications

References 10 publications

The Earth's magnetopause as a source and sink for equatorial nightside energetic charged particles

The Earth's magnetopause as a source and sink for equatorial nightside energetic charged particles

Plasma density features associated with strong convection in the winter high‐latitude F region

On the supply of heavy planetary material to the magnetotail of Mercury

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